Pencil lead sharpening machine



ch. 2, 1951 H LE R ADAMS 2,569,548 7 v PENCIL LEAD SHARPENING MACHINE Filed June 13, 1949 u I u INVEVTOR. Hwe 15/90) Ayn/vs Patented Oct. 2, 1951 PENCIL LEAD SHARPENIN G .MACHINE Harry Le Roy Adams, Denver, 0010., assignor of v one-tenth to Veda G. Jones Application June 13, 1949, Serial No. 98,760

1 This invention relates to a pencil lead sharpener, and is not to be confused with the conventional pencil sharpener, since it serves no function in sharpening anything other than pencil lead. It is more particularly designed for use by photo retouchers. Such use requires an extremely long, delicately and accurately sharpened lead. The sharpened lead is held in a holder for use.

The principal object of this invention is to provide a simple, accurate, rapid, and easily used device which will place an extremely long, sharp, delicate point on a pencil lead.

Another object of the invention is to so construct the device that it will require but a minimumof space, and so that it can be mounted or rested on any retouching board or table.

It is extremely essential that the points on retouche'rsf leads beabsolutelyuniform and round without flat spots or other irregularities. A further object of this invention is to provide a lead pointer which will operate uniformly about the entire circumfererence of the lead to produce an accurate circular, concentric point.

- Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a top view of the improved pencil lead sharpener;

Fig. 2 is a side view thereof;

Fig. 3 is a top view, with an upper cover plate removed;

Fig. 4 is a cross-section, taken on the. line 4-4, Fig. 1;

Fig. 5 is a similar cross-section, taken on the line .5-5, Fig. 3; and

Fig. 6 is a detail fragmentary section illustrating a belt roller used in the improved lead sharpening device.

The improved lead sharpener comprises a circular base I0 having a centrally positioned, stationary belt cylinder l I arising therefrom. The cylinder H is surrounded by an upstanding circular flange I2, about which a preferably transparent wall I 3 of plastic or similar material is positioned.

An axial hub portion 3| arises within the cylinder II. The wall I3, the belt cylinder II, and

4 Claims. (Cl. 120- 94) the hub portion 3'lextend upwardly from the base I0 to a uniform height. A rotating cover plate l4 closes the'entire top of the wall [3. An axis stud I5- is secured at the axis of the cover plate M by means of a suitable clamp screw l6. The axis stud l5 extends downwardly into and is freely rotatable within a vertical, axial bore I! in the hub portion 3|.

An idler roller IB is eccentrically mounted on the cover plate M and extends downwardly therefrom. The roller I8 is mounted on a roller shaft l9 which'is secured beneath the cover plate M by means of an attachment screw 20. A headed screw 2! in the bottom of the shaft 19 retains the roller l8 in place therein. The roller is preferably knurled or roughened On its exterior surface, as shown in Fig. 6. An endless flexible belt 29 of abrasive material, such as emery cloth, surrounds the roller l8 and the central cylinder II.

The cover plate I4 is provided with a collet opening surrounded by an upstanding circular flange 22. A lead supporting collet 23 is rotat-- ably'mounted in the circular flange 22 and pro-.

vided with a vertical axial bore through which the lead to be sharpened, indicated at 21, extends. The collet 23 is provided with an enlarged, knurled finger grip portion 26 which supports the collet on the flange 22. The lead 21 is supported in the collet 23 b means of a coiled tension spring 24 which extends across the bore of the collet in a notch 28 and bears against the side of the lead. The spring is attached at its two extremities to the finger portion 26 by means of suitable attachment screws 25.

The collet is so positioned with reference to the belt 22 that the lead 21 will force the band inwardly between the cylinder H and the roller l8 at one side as shown in Fig. 3.

In use, the lead is inserted downwardly through the collet 23 until its lower extremity is adjacent the bottom edge of the belt 29. It is supported in this position by the spring 24. The portion 26 of the collet is then gripped between the thumb and finger and the cover plate I4 is rotated about its axis by means of the collet.

It will be noted that since the collet is stripped by the hand of the user the lead does not rotate with reference to the hand. However, it does move in an orbit about the cylinder ll so as to constantly present new sides to the belt 29 in successive progression. The planetary movement of the lead about the axis of the cylinder ll causes the roller l8 to rotate about its axis in a direction opposite to the revolution of the cover plate I4. This causes the abrasive belt to continuously travel past the lead to grind the latter to a sharp point. The pressure of the belt against the lead is caused by the tension placed therein due to the rotation of the roller l8. This tension is exceedingly gentle so that along, sharp tapering point results therefrom.

The upper edge of the cylinder l I is turned inwardly to form a dust-retaining flange 30 which tends to prevent the lead dust from overflowing the cylinder.

While a specific form of the improvement has been described and illustrated herein, it is to be understood that the same may bevaried, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. A pencil lead sharpener comprising: a fixed cylinder; an idler roller of uniform diameter throughout its length positioned eccentrically of said cylinder with its axis parallel to the axis of said cylinder; means for causing said roller to travel in a circular orbit about said cylinder; an endless abrasive belt surrounding said cylinder and said roller; and means for holding a pencil lead in a transverse position against and across said belt between said cylinder and said roller during the orbitual movement of the latter.

2. A pencil lead sharpener comprising: a fixed cylinder; a rotatable plate pivoted at the axis of said cylinder at one extremity thereof; an idler roller ofuniform diameter throughout its length carried by said plate at one side of said cylinder and parallel thereto; an endless abrasive belt extending about both said cylinder and said roller; a' lead guiding collet rotatably mounted in said plate and having an axial bore for receiving said pencil lead, said collet being positioned so that said lead will bear against said abrasive belt in a transverse position between said cylinder and said roller, so that when said plate is rotated said belt will be caused to travel transversally across said lead.

3. A device for sharpening a pencil lead comprising: a base; a stationary belt cylinder aflixed to and arising axially from said base; a hub portion within said belt cylinder; a cover plate rotatably mounted on said hub portion; a roller shaft mounted on said cover plate eccentrically of said belt cylinder; a cylindrical roller of smaller diameter than said belt cylinder mounted to freely rotate about said roller shaft; an endless, flexible, abrasive belt extending horizontally about said belt cylinder and said roller so as to have two vertical, normally straight sides extending tangentially between said belt cylinder and said roller, there being a collet opening in said cover plate over one of said straight sides of said belt; and a lead-supporting collet rotatably mounted in said opening, there being a vertical axial bore in said collet for supporting a vertical pencil lead transversally across the horizontal path of said belt, the axis of said collet being so placed that the normally straight side of the belt over which it is placed will be flexed inwardly by a pencil lead in said bore so that the driving tension in said belt will act to pull the latter against and across said lead when said cover plate is rotated.

4. A device for sharpening a pencil lead having a construction as recited in claim 3 in which means are provided in said collet for engaging and supporting the pencil lead therein.

HARRY LE ROY ADAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date- 2,359,093 Eastman Sept. 26, 1944 FOREIGN PATENTS Number Country Date I 2,344 Great Britain Jan. 29, 1912 103,732 Sweden Dec. 11, 1941 

